Energy services giant Halliburton has admitted that it has fired two members of staff in Iraq for taking kickbacks of up to $6m (£3.3m).

The two employees are alleged to have taken the cash from an unnamed Kuwaiti company helping Halliburton to supply US troops in Iraq.

Both workers were employed by KBR, a Halliburton subsidiary.

In a separate case, Halliburton is being accused of overcharging US forces in Iraq for their fuel deliveries.

Pentagon auditors are continuing to investigate that allegation.

Controversy continues

Regarding the kickback sackings, Halliburton spokeswoman Wendy Hall said the company had reported the "irregularities" to the authorities.

"We found it quickly, and we immediately reported it," she added.

"We do not tolerate this kind of behaviour by anyone at any level in any Halliburton company."

American Halliburton has won a lion's share of US contracts to rebuild Iraq, a fact that has itself created a fair amount of controversy due to the firm's close connections with leading members of the George W Bush government.

US Vice President Dick Cheney was formerly Halliburton chief executive.